Biology Exam #1

nitrogenous base

Which component of a DNA molecule encodes the genetic information necessary to build a functioning organism? Please choose the correct answer from the following choices, and then select the submit answer button. glycerol head double helix nitrogenous bases hydrogen bonds sugar-phosphate backbone

cholesterol

Which lipid is an important component of most cell membranes?

Macromolecules

______________ are large molecules, made from smaller building blocks.

polysaccharide

a complex carbohydrate composed of a chain of monosaccharides joined together

Scientific Literacy

a general, fact-based understanding of biology and other sciences

An independent variable can: a. cause a change in the dependent variable b. Is plotted on the y-axis c. can be controlled less than a dependent variable d. is more important that a dependent variable

a. Can cause a change in the dependent variable

Which of the following is an organic molecule? Please choose the correct answer from the following choices, and then select the submit answer button. a. glycine (C2H5NO2) b. potassium nitrate (KNO3) c. calcium chloride (CaCl2) d. nitrogen dioxide (NO2) e. salt (NaCl)

a. glycine (C2H5NO2)

Identify the macromolecule that is not considered to be organic.

all macromolecules are organic

Which of the following statements is false? Please choose the correct answer from the following choices, and then select the submit answer button. a. All fats are lipids, but not all lipids are fats. b. All fats are lipids. Conversely, all lipids are also fats. c. Lipids do not have subunit structures, such as the subunits that make up carbohydrates. They are identified based on physical characteristics. d. Sterols primarily function to regulate growth and development. e. Lipids have three functions: long-term energy storage and insulation, membrane formation, and composition of hormones.

b. All fats are lipids. Conversely, all lipids are also fats.

Because enzymes are proteins, they are sensitive to denaturing conditions that disrupt protein structure. Which of the following is not an example of a denaturing condition? Please choose the correct answer from the following choices, and then select the submit answer button. a. increases in temperature b. All of the above are examples of denaturing conditions. c. high salt concentration d. low salt concentration e. changes in pH

b. All of the above are examples of denaturing conditions.

Dietary proteins: a. consist of all 20 amino acids required in the human body. b. are considered "complete" only if they contain all of the essential amino acids required by humans. c. are considered "complete" only if they contain all of the non-essential amino acids required by humans. d. are nutritionally identical, because all are broken down into their constituent amino acids in the digestive system. e. can be obtained from animal sources, but not plant sources.

b. are considered "complete" only if they contain all of the essential amino acids required by humans.

All lipids are: Please choose the correct answer from the following choices, and then select the submit answer button. a. triglycerides that serve as an energy source. b. nonpolar and insoluble in water. c. modified forms of cholesterol. d. phospholipids that form cell membranes. e. used for short-term energy storage.

b. nonpolar and insoluble in water.

In a nucleic acid, adjacent nucleotides are bound to each other in what way? Please choose the correct answer from the following choices, and then select the submit answer button. a. base to phosphate group b. phosphate group to sugar c. phosphate group to phosphate group d. sugar to sugar e. base to base

b. phosphate group to sugar

Covalent Bonds

bonding between molecules that share electrons

Ionic Bonds

bonding between oppositely charged molecules (ions); involves the transfer of electrons

Blood pH acts as a

buffer

Which statement about amino acids is false? a. They are monomers. b. They combine to form proteins. c. They are distinguished from each other by variation in their carboxyl groups. d. They come in polar, nonpolar, and electrically charged forms. e. They are organic molecules possessing both carboxyl and amino groups.

c. They are distinguished from each other by variation in their carboxyl groups.

Animal fats and plant oils are sometimes used as sources of fuel for automobile engines. How is energy harvested from these molecules? Please choose the correct answer from the following choices, and then select the submit answer button. a. They contain long carbon tails and each atom has unpaired electrons that are released upon exposure to extreme heat and pressure. b. They contain hydrocarbon tails linked by disulfide bridges that, when broken, release chemical energy. c. They contain long chains of hydrocarbons that, when broken, release the energy stored in the bonds linking the atoms together. d. They contain multiple phosphate groups that each release energy when "liberated" from the molecule chemically. e. They contain long hydrophobic regions that, when mixed with water, generate explosions.

c. They contain long chains of hydrocarbons that, when broken, release the energy stored in the bonds linking the atoms together.

DNA is sometimes described as a ladder-shaped molecule. What would be the BEST description of the composition of the rail portion that runs up each side of the ladder? Please choose the correct answer from the following choices, and then select the submit answer button. a. a chain of nitrogen-containing bases b. a chain of RNA nucleotides c. a chain of alternating sugars and phosphates d. a chain of sugars e. a chain of alternating sugars and bases

c. a chain of alternating sugars and phosphates

An enzyme that can bind to and break apart molecules of lactose will: a. also be able to bind fatty acids. b. also be able to bind sucrose. c. only be able to bind lactose. d. also be able to bind starch. e. also be able to bind amino acids.

c. only be able to bind lactose.

In terms of structural materials, _______ is to plants as _______ is to lobsters and crabs.

cellulose, chitin

Independent Variable

changed by scientist. There can only be one

Organic Molecules

chemical compounds that contain both carbon and hydrogen

Buffers

chemicals that act to resist changes in pH can quickly absorb excess H+ ions to keep a solution from becoming too acidic Can quickly release H+ ions to contract any increases in OH- concentration

All of the following are lipids except: triglycerides. steroids. insulin. cholesterol. fats.

cholesterol

Dietary Fiber

clears digestive tract and reduces risk of disease

Which of the following is not a characteristic of unsaturated fats? Please choose the correct answer from the following choices, and then select the submit answer button. a. They are liquid at room temperature. b. They are generally derived from plant sources. c. Their molecules are loosely packed together. d. They are generally derived from animal sources. e. They are found in both peanuts and olive oil.

d. They are generally derived from animal sources.

y-axis

dependent variable

Which of the following statements about DNA and nucleic acids is TRUE? Please choose the correct answer from the following choices, and then select the submit answer button. a. Nucleic acids are essential to the building and functioning of organisms, along with carbohydrates, proteins, and lipids. b. DNA is a polar molecule: the bases provide a hydrophobic interior, and the sugar-phosphate backbone is hydrophilic. c. Nucleic acids come in two types: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). d. A 10-unit nucleic acid would have 10 bases. e. All of the above.

e. All of the above.

Why would you expect the energy present in the bonds of glucose to be more readily available than the energy from the sugar lactose? a. Lactose is a complex carbohydrate and requires a lot of breaking down before the energy can be accessed. b. It is easier to break down glucose into its component monosaccharides. c. Glucose has fewer double bonds than lactose, making it easier to break down. d. Both glucose and lactose are simple sugars; some people, however, have difficulty breaking down lactose. e. Glucose is a simple sugar, and no additional processing is necessary to access the energy in the carbon-hydrogen bonds.

e. Glucose is a simple sugar, and no additional processing is necessary to access the energy in the carbon-hydrogen bonds.

When you fry an egg, the clear protein turns opaque white. What phenomenon are you observing? Please choose the correct answer from the following choices, and then select the submit answer button. a. High temperatures can cause a protein to lose both its primary and secondary structure. b. High temperatures can cause a protein to lose its primary structure. c. High pH can denature a protein. d. Low pH can denature a protein. e. High temperatures can cause a protein to lose both its secondary and tertiary structure.

e. High temperatures can cause a protein to lose both its secondary and tertiary structure.

Which of the following is not a fate of glucose circulating in the blood of a healthy individual? a. It is used as fuel for cellular activities. b. It is transported into cells. c. It can be stored as glycogen until it is needed for energy. d. It can be converted to fat. e. It can remain, circulating in the blood indefinitely.

e. It can remain, circulating in the blood indefinitely.

Lipids are made up of long hydrocarbon chains, composed of all carbon and hydrogen atoms. This characteristic makes lipids insoluble in water ("oil and water don't mix") because: Please choose the correct answer from the following choices, and then select the submit answer button. a. hydrocarbons are hydrophilic. b. hydrocarbons are polar. c. hydrocarbons are commonly found in plants, where they push water to the tops of plants. d. hydrocarbons form the rigid outer skeletons of crabs and lobsters, which repel water. e. hydrocarbons are nonpolar.

e. hydrocarbons are nonpolar.

Which of the following describes how complex carbohydrates—particularly starches that have not been highly processed—are broken down and used for energy? a. They are used as structural molecules and not used for energy. b. They are immediately broken down, releasing a large burst of energy. c. They are immediately broken down, providing a steady level of energy. d.The bonds between glucose molecules are broken slowly, resulting in a large burst of energy. e.They are slowly broken down over time, providing a steady level of energy.

e.They are slowly broken down over time, providing a steady level of energy.

valence electrons

electrons in the outermost shell

Glucose, Fructose, Galactose

examples of monosaccharides/ simple sugars

3 types of lipids

fat, sterols, and phospholipids

What is the primary role of carbohydrates in living organisms?

fuel for cellular mechanisms

What is the weakest type of bonding

hydrogen

x-axis

independent variable

Pseudoscience

individuals make scientific-sounding claims that are not supported by trustworthy, medical scientific studies

Lipids

insoluble in water-- function: energy storage ex: oils and fats

Identify the molecule that is not a carbohydrate. Please choose the correct answer from the following choices, and then select the submit answer button. galactose glucose lactase fructose lactose

lactase

fats function

long term energy storage

fat

long term storage for energy

Enzymes

lower the activation energy needed for a reaction to occur.

Water has a _____ density when frozen and is a good ____

lower, solvent

Atoms bond together to form

molecules

More H+ =

more acidic

More OH- =

more basic

Ionic compounds are

neutral

The scientific method is _____ not _____

objective, subjective

Which of the following types of food would be considered a "fat"? Please choose the correct answer from the following choices, and then select the submit answer button. bread honey oils lean meats table sugar

oils

What are the essential components of all nucleotides?

phosphate group, sugar molecule, nitrogen- containing molecule

Starch

plants primary form of energy storage as a complex carbohydrate

Replication

process of repeating a study

Radioisotopes

radioactive atoms; unstable isotopes/ atoms that break down ex: Lithium

Scientific Thinking

rationale, based on observations/ experiences, testable, repeatable, can be corrected if need be

Isotopes

same number of protons but different number of neutrons

Monosaccharides

simple sugars which contain anywhere from 3-6 Carbon atoms and when broken down produce molecules that usually are not carbohydrates

Elements

something that cannot be broken down chemically into anything smaller

chitin and cellulose

structural carbohydrates that are not digestable

glycogen

temporary storage of energy

The chemical behavior of an atom is determined by

the distribution of electrons in electron shells

Generally speaking, the greater the number of double bonds in a triglyceride:

the more "kinks" there are in the hydrocarbon tails.

Atomic number

the number of protons in the nucleus of an atom

Blind experimental design

the participant is unaware of what is happening

Placebo Effect

the phenomenon in which the expectations of the participants in a study can influence their behavior

Carbohydrates

the primary fuel for cells which forms cell structure sugars [C,H,O]

Double blind experiment

the scientist and the participant are unaware

Trans fats are more likely to accumulate in blood vessels because

they are less reactive

The secondary structure of a protein refers to the:

twisting of the amino acid chain into a corkscrew-like shape or zigzag folding pattern.

What has a high heat capacity?

water

Disaccharide

A double sugar molecule made of two monosaccharides ex: lactose & sucrose

Atomic Weight

Average of the mass numbers of all isotopes

Anecdotal Observations

Based only on 1 or a few observations, people conclude that there is or is not a link--- MISLEADING

Hydrogen Bonding

Bonding with a hydrogen molecule

carbohydrates

Dietary fiber is composed of

saturation

Increasing a fat's degree of ________ changes its consistency and makes it more solid at room temperatures.

4 types of macromolecules

Lipids, carbohydrates, proteins, and nucleic acids

Ions

Molecules that have a charge

Atomic Mass

Number of protons and neutrons

Dependent Variable

Outcome in response to the independent variable. Caused by and depends on the independent variable- more than 1

What are the "Big Four"?

Oxygen-65% Carbon-18.5% Hydrogen-9.5% Nitrogen- 3%

Macromolecules

Smaller building blocks that combine to make an organic molecule

proteins

The DNA you inherited from your parents provides the instructions to make

Biological literacy

The ability to 1. use scientific inquiry to think creatively about real- world issues with a biological slant 2. communicate these thoughts to others 3. Use this information to make decisions

Scientific Method

1. Make observations 2. Formulate hypothesis 3. Devise a testable prediction 4. conduct a critical experiment 5. draw conclusions and make revisions

How many elements are in your body?

25

A carbohydrate molecule is discovered that contains 28 carbon atoms. Based on what you know about the chemical composition of carbohydrates, this molecule likely will have ____ hydrogen atoms and ____ oxygen atoms.

56, 28

What elements do organic molecules possess?

Carbon, Oxygen, Hydrogen

muscles and liver

Glucose is stored for short periods of time, primarily in the cells of the:

Pure water has equal amounts of __ and __?

H+ and OH-

Dissolved materials influence the ratio of

H+ to OH-

Theory

Has been tested many times, is certain, and has not failed

Statistics

Helps to quantify and summarize large amounts of data

When you fry an egg, the clear protein turns opaque white. What phenomenon are you observing?

High temperatures can cause a protein to lose both its secondary and tertiary structure.

randomized experiment

The subjects do not know what they are receiving

What do a bacterium and a daisy have in common?

They are made from organic molecules

Controlled Variable

Things that a scientist wants to remain constant